/*

   * Interface handling (except master interface)
   *

   * Copyright 2002-2005, Instant802 Networks, Inc.
   * Copyright 2005-2006, Devicescape Software, Inc.
   * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>

   * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/if_arp.h>
  #include <linux/netdevice.h>
  #include <linux/rtnetlink.h>
  #include <net/mac80211.h>

  #include <net/ieee80211_radiotap.h>

  #include "ieee80211_i.h"
  #include "sta_info.h"

  #include "debugfs_netdev.h"

  #include "mesh.h"

  #include "led.h"

  #include "driver-ops.h"

  #include "wme.h"

  #include "rate.h"

  /**
   * DOC: Interface list locking
   *
   * The interface list in each struct ieee80211_local is protected
   * three-fold:
   *
   * (1) modifications may only be done under the RTNL
   * (2) modifications and readers are protected against each other by
   *     the iflist_mtx.
   * (3) modifications are done in an RCU manner so atomic readers
   *     can traverse the list in RCU-safe blocks.
   *
   * As a consequence, reads (traversals) of the list can be protected
   * by either the RTNL, the iflist_mtx or RCU.
   */

  static int ieee80211_change_mtu(struct net_device *dev, int new_mtu)
  {
  	int meshhdrlen;
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  
  	meshhdrlen = (sdata->vif.type == NL80211_IFTYPE_MESH_POINT) ? 5 : 0;
  
  	/* FIX: what would be proper limits for MTU?
  	 * This interface uses 802.3 frames. */
  	if (new_mtu < 256 ||
  	    new_mtu > IEEE80211_MAX_DATA_LEN - 24 - 6 - meshhdrlen) {
  		return -EINVAL;
  	}
  
  #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
  	printk(KERN_DEBUG "%s: setting MTU %d
  ", dev->name, new_mtu);
  #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
  	dev->mtu = new_mtu;
  	return 0;
  }

  static int ieee80211_change_mac(struct net_device *dev, void *addr)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct sockaddr *sa = addr;

  	int ret;

  	if (ieee80211_sdata_running(sdata))

  		return -EBUSY;

  	ret = eth_mac_addr(dev, sa);

  
  	if (ret == 0)

  		memcpy(sdata->vif.addr, sa->sa_data, ETH_ALEN);

  
  	return ret;
  }

  static inline int identical_mac_addr_allowed(int type1, int type2)
  {
  	return type1 == NL80211_IFTYPE_MONITOR ||
  		type2 == NL80211_IFTYPE_MONITOR ||
  		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_WDS) ||
  		(type1 == NL80211_IFTYPE_WDS &&
  			(type2 == NL80211_IFTYPE_WDS ||
  			 type2 == NL80211_IFTYPE_AP)) ||
  		(type1 == NL80211_IFTYPE_AP && type2 == NL80211_IFTYPE_AP_VLAN) ||
  		(type1 == NL80211_IFTYPE_AP_VLAN &&
  			(type2 == NL80211_IFTYPE_AP ||
  			 type2 == NL80211_IFTYPE_AP_VLAN));
  }

  static int ieee80211_check_concurrent_iface(struct ieee80211_sub_if_data *sdata,
  					    enum nl80211_iftype iftype)

  {

  	struct ieee80211_local *local = sdata->local;

  	struct ieee80211_sub_if_data *nsdata;
  	struct net_device *dev = sdata->dev;

  	ASSERT_RTNL();

  
  	/* we hold the RTNL here so can safely walk the list */
  	list_for_each_entry(nsdata, &local->interfaces, list) {
  		struct net_device *ndev = nsdata->dev;

  		if (ndev != dev && ieee80211_sdata_running(nsdata)) {

  			/*
  			 * Allow only a single IBSS interface to be up at any
  			 * time. This is restricted because beacon distribution
  			 * cannot work properly if both are in the same IBSS.
  			 *
  			 * To remove this restriction we'd have to disallow them
  			 * from setting the same SSID on different IBSS interfaces
  			 * belonging to the same hardware. Then, however, we're
  			 * faced with having to adopt two different TSF timers...
  			 */

  			if (iftype == NL80211_IFTYPE_ADHOC &&

  			    nsdata->vif.type == NL80211_IFTYPE_ADHOC)
  				return -EBUSY;
  
  			/*
  			 * The remaining checks are only performed for interfaces
  			 * with the same MAC address.
  			 */
  			if (compare_ether_addr(dev->dev_addr, ndev->dev_addr))
  				continue;
  
  			/*
  			 * check whether it may have the same address
  			 */

  			if (!identical_mac_addr_allowed(iftype,

  							nsdata->vif.type))
  				return -ENOTUNIQ;
  
  			/*
  			 * can only add VLANs to enabled APs
  			 */

  			if (iftype == NL80211_IFTYPE_AP_VLAN &&

  			    nsdata->vif.type == NL80211_IFTYPE_AP)
  				sdata->bss = &nsdata->u.ap;
  		}
  	}

  	return 0;
  }

  void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata,
  				    const int offset)
  {
  	struct ieee80211_local *local = sdata->local;
  	u32 flags = sdata->u.mntr_flags;
  
  #define ADJUST(_f, _s)	do {					\
  	if (flags & MONITOR_FLAG_##_f)				\
  		local->fif_##_s += offset;			\
  	} while (0)
  
  	ADJUST(FCSFAIL, fcsfail);
  	ADJUST(PLCPFAIL, plcpfail);
  	ADJUST(CONTROL, control);
  	ADJUST(CONTROL, pspoll);
  	ADJUST(OTHER_BSS, other_bss);
  
  #undef ADJUST
  }

  /*
   * NOTE: Be very careful when changing this function, it must NOT return
   * an error on interface type changes that have been pre-checked, so most
   * checks should be in ieee80211_check_concurrent_iface.
   */
  static int ieee80211_do_open(struct net_device *dev, bool coming_up)

  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct sta_info *sta;
  	u32 changed = 0;
  	int res;
  	u32 hw_reconf_flags = 0;

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_WDS:
  		if (!is_valid_ether_addr(sdata->u.wds.remote_addr))
  			return -ENOLINK;
  		break;

  	case NL80211_IFTYPE_AP_VLAN: {
  		struct ieee80211_sub_if_data *master;

  		if (!sdata->bss)
  			return -ENOLINK;

  		list_add(&sdata->u.vlan.list, &sdata->bss->vlans);

  
  		master = container_of(sdata->bss,
  				      struct ieee80211_sub_if_data, u.ap);
  		sdata->control_port_protocol =
  			master->control_port_protocol;
  		sdata->control_port_no_encrypt =
  			master->control_port_no_encrypt;

  		break;

  		}

  	case NL80211_IFTYPE_AP:
  		sdata->bss = &sdata->u.ap;
  		break;
  	case NL80211_IFTYPE_MESH_POINT:

  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_MONITOR:
  	case NL80211_IFTYPE_ADHOC:
  		/* no special treatment */
  		break;
  	case NL80211_IFTYPE_UNSPECIFIED:

  	case NUM_NL80211_IFTYPES:

  	case NL80211_IFTYPE_P2P_CLIENT:
  	case NL80211_IFTYPE_P2P_GO:

  		/* cannot happen */
  		WARN_ON(1);
  		break;
  	}
  
  	if (local->open_count == 0) {

  		res = drv_start(local);

  		if (res)
  			goto err_del_bss;

  		if (local->ops->napi_poll)
  			napi_enable(&local->napi);

  		/* we're brought up, everything changes */
  		hw_reconf_flags = ~0;

  		ieee80211_led_radio(local, true);

  		ieee80211_mod_tpt_led_trig(local,
  					   IEEE80211_TPT_LEDTRIG_FL_RADIO, 0);

  	}
  
  	/*

  	 * Copy the hopefully now-present MAC address to
  	 * this interface, if it has the special null one.

  	 */

  	if (is_zero_ether_addr(dev->dev_addr)) {
  		memcpy(dev->dev_addr,
  		       local->hw.wiphy->perm_addr,
  		       ETH_ALEN);
  		memcpy(dev->perm_addr, dev->dev_addr, ETH_ALEN);
  
  		if (!is_valid_ether_addr(dev->dev_addr)) {
  			if (!local->open_count)
  				drv_stop(local);
  			return -EADDRNOTAVAIL;

  		}

  	}

  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:
  		/* no need to tell driver */
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
  			local->cooked_mntrs++;
  			break;
  		}
  
  		/* must be before the call to ieee80211_configure_filter */
  		local->monitors++;

  		if (local->monitors == 1) {

  			local->hw.conf.flags |= IEEE80211_CONF_MONITOR;
  			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;

  		}

  		ieee80211_adjust_monitor_flags(sdata, 1);

  		ieee80211_configure_filter(local);

  
  		netif_carrier_on(dev);

  		break;

  	default:

  		if (coming_up) {

  			res = drv_add_interface(local, sdata);

  			if (res)
  				goto err_stop;
  		}

  		if (sdata->vif.type == NL80211_IFTYPE_AP) {

  			local->fif_pspoll++;

  			local->fif_probe_req++;

  			ieee80211_configure_filter(local);

  		} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  			local->fif_probe_req++;

  		}

  		changed |= ieee80211_reset_erp_info(sdata);
  		ieee80211_bss_info_change_notify(sdata, changed);

  		if (sdata->vif.type == NL80211_IFTYPE_STATION ||
  		    sdata->vif.type == NL80211_IFTYPE_ADHOC)

  			netif_carrier_off(dev);
  		else
  			netif_carrier_on(dev);

  
  		/*
  		 * set default queue parameters so drivers don't
  		 * need to initialise the hardware if the hardware
  		 * doesn't start up with sane defaults
  		 */
  		ieee80211_set_wmm_default(sdata);

  	}

  	set_bit(SDATA_STATE_RUNNING, &sdata->state);

  	if (sdata->vif.type == NL80211_IFTYPE_WDS) {
  		/* Create STA entry for the WDS peer */
  		sta = sta_info_alloc(sdata, sdata->u.wds.remote_addr,
  				     GFP_KERNEL);
  		if (!sta) {
  			res = -ENOMEM;
  			goto err_del_interface;
  		}

  		sta_info_move_state(sta, IEEE80211_STA_AUTH);
  		sta_info_move_state(sta, IEEE80211_STA_ASSOC);
  		sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);

  
  		res = sta_info_insert(sta);
  		if (res) {
  			/* STA has been freed */
  			goto err_del_interface;
  		}

  
  		rate_control_rate_init(sta);

  	}

  	/*
  	 * set_multicast_list will be invoked by the networking core
  	 * which will check whether any increments here were done in
  	 * error and sync them down to the hardware as filter flags.
  	 */
  	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
  		atomic_inc(&local->iff_allmultis);
  
  	if (sdata->flags & IEEE80211_SDATA_PROMISC)
  		atomic_inc(&local->iff_promiscs);

  	mutex_lock(&local->mtx);

  	hw_reconf_flags |= __ieee80211_recalc_idle(local);

  	mutex_unlock(&local->mtx);

  	if (coming_up)
  		local->open_count++;

  	if (hw_reconf_flags)

  		ieee80211_hw_config(local, hw_reconf_flags);

  	ieee80211_recalc_ps(local, -1);

  	netif_tx_start_all_queues(dev);

  
  	return 0;
   err_del_interface:

  	drv_remove_interface(local, sdata);

   err_stop:

  	if (!local->open_count)
  		drv_stop(local);

   err_del_bss:
  	sdata->bss = NULL;
  	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
  		list_del(&sdata->u.vlan.list);

  	clear_bit(SDATA_STATE_RUNNING, &sdata->state);

  	return res;
  }

  static int ieee80211_open(struct net_device *dev)

  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	int err;
  
  	/* fail early if user set an invalid address */

  	if (!is_valid_ether_addr(dev->dev_addr))

  		return -EADDRNOTAVAIL;
  
  	err = ieee80211_check_concurrent_iface(sdata, sdata->vif.type);
  	if (err)
  		return err;
  
  	return ieee80211_do_open(dev, true);
  }
  
  static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
  			      bool going_down)
  {

  	struct ieee80211_local *local = sdata->local;

  	unsigned long flags;
  	struct sk_buff *skb, *tmp;

  	u32 hw_reconf_flags = 0;

  	int i;

  	enum nl80211_channel_type orig_ct;

  	clear_bit(SDATA_STATE_RUNNING, &sdata->state);

  	if (local->scan_sdata == sdata)
  		ieee80211_scan_cancel(local);

  	/*
  	 * Stop TX on this interface first.
  	 */

  	netif_tx_stop_all_queues(sdata->dev);

  
  	/*

  	 * Purge work for this interface.
  	 */
  	ieee80211_work_purge(sdata);
  
  	/*

  	 * Remove all stations associated with this interface.
  	 *
  	 * This must be done before calling ops->remove_interface()
  	 * because otherwise we can later invoke ops->sta_notify()
  	 * whenever the STAs are removed, and that invalidates driver
  	 * assumptions about always getting a vif pointer that is valid
  	 * (because if we remove a STA after ops->remove_interface()
  	 * the driver will have removed the vif info already!)
  	 *

  	 * This is relevant only in AP, WDS and mesh modes, since in
  	 * all other modes we've already removed all stations when
  	 * disconnecting etc.

  	 */
  	sta_info_flush(local, sdata);
  
  	/*
  	 * Don't count this interface for promisc/allmulti while it
  	 * is down. dev_mc_unsync() will invoke set_multicast_list
  	 * on the master interface which will sync these down to the
  	 * hardware as filter flags.
  	 */
  	if (sdata->flags & IEEE80211_SDATA_ALLMULTI)
  		atomic_dec(&local->iff_allmultis);
  
  	if (sdata->flags & IEEE80211_SDATA_PROMISC)
  		atomic_dec(&local->iff_promiscs);

  	if (sdata->vif.type == NL80211_IFTYPE_AP) {

  		local->fif_pspoll--;

  		local->fif_probe_req--;
  	} else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
  		local->fif_probe_req--;
  	}

  	netif_addr_lock_bh(sdata->dev);

  	spin_lock_bh(&local->filter_lock);

  	__hw_addr_unsync(&local->mc_list, &sdata->dev->mc,
  			 sdata->dev->addr_len);

  	spin_unlock_bh(&local->filter_lock);

  	netif_addr_unlock_bh(sdata->dev);

  	ieee80211_configure_filter(local);

  	del_timer_sync(&local->dynamic_ps_timer);
  	cancel_work_sync(&local->dynamic_ps_enable_work);

  
  	/* APs need special treatment */
  	if (sdata->vif.type == NL80211_IFTYPE_AP) {

  		struct ieee80211_sub_if_data *vlan, *tmpsdata;

  		struct beacon_data *old_beacon =
  			rtnl_dereference(sdata->u.ap.beacon);

  		struct sk_buff *old_probe_resp =
  			rtnl_dereference(sdata->u.ap.probe_resp);

  		/* sdata_running will return false, so this will disable */
  		ieee80211_bss_info_change_notify(sdata,
  						 BSS_CHANGED_BEACON_ENABLED);

  		/* remove beacon and probe response */

  		RCU_INIT_POINTER(sdata->u.ap.beacon, NULL);

  		RCU_INIT_POINTER(sdata->u.ap.probe_resp, NULL);

  		synchronize_rcu();
  		kfree(old_beacon);

  		kfree_skb(old_probe_resp);

  
  		/* down all dependent devices, that is VLANs */

  		list_for_each_entry_safe(vlan, tmpsdata, &sdata->u.ap.vlans,

  					 u.vlan.list)
  			dev_close(vlan->dev);
  		WARN_ON(!list_empty(&sdata->u.ap.vlans));

  
  		/* free all potentially still buffered bcast frames */
  		local->total_ps_buffered -= skb_queue_len(&sdata->u.ap.ps_bc_buf);
  		skb_queue_purge(&sdata->u.ap.ps_bc_buf);

  	}

  	if (going_down)
  		local->open_count--;

  
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP_VLAN:
  		list_del(&sdata->u.vlan.list);
  		/* no need to tell driver */
  		break;
  	case NL80211_IFTYPE_MONITOR:
  		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) {
  			local->cooked_mntrs--;
  			break;
  		}
  
  		local->monitors--;

  		if (local->monitors == 0) {

  			local->hw.conf.flags &= ~IEEE80211_CONF_MONITOR;
  			hw_reconf_flags |= IEEE80211_CONF_CHANGE_MONITOR;

  		}

  		ieee80211_adjust_monitor_flags(sdata, -1);

  		ieee80211_configure_filter(local);

  		break;

  	default:

  		flush_work(&sdata->work);

  		/*
  		 * When we get here, the interface is marked down.
  		 * Call synchronize_rcu() to wait for the RX path
  		 * should it be using the interface and enqueuing
  		 * frames at this very time on another CPU.
  		 */
  		synchronize_rcu();
  		skb_queue_purge(&sdata->skb_queue);

  		/*

  		 * Disable beaconing here for mesh only, AP and IBSS
  		 * are already taken care of.

  		 */

  		if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)

  			ieee80211_bss_info_change_notify(sdata,
  				BSS_CHANGED_BEACON_ENABLED);

  		/*
  		 * Free all remaining keys, there shouldn't be any,
  		 * except maybe group keys in AP more or WDS?
  		 */

  		ieee80211_free_keys(sdata);

  		if (going_down)

  			drv_remove_interface(local, sdata);

  	}
  
  	sdata->bss = NULL;

  	mutex_lock(&local->mtx);

  	hw_reconf_flags |= __ieee80211_recalc_idle(local);

  	mutex_unlock(&local->mtx);

  
  	ieee80211_recalc_ps(local, -1);

  	if (local->open_count == 0) {

  		if (local->ops->napi_poll)
  			napi_disable(&local->napi);

  		ieee80211_clear_tx_pending(local);

  		ieee80211_stop_device(local);

  		/* no reconfiguring after stop! */
  		hw_reconf_flags = 0;

  	}

  	/* Re-calculate channel-type, in case there are multiple vifs
  	 * on different channel types.
  	 */
  	orig_ct = local->_oper_channel_type;
  	ieee80211_set_channel_type(local, NULL, NL80211_CHAN_NO_HT);

  	/* do after stop to avoid reconfiguring when we stop anyway */

  	if (hw_reconf_flags || (orig_ct != local->_oper_channel_type))

  		ieee80211_hw_config(local, hw_reconf_flags);

  	spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
  	for (i = 0; i < IEEE80211_MAX_QUEUES; i++) {
  		skb_queue_walk_safe(&local->pending[i], skb, tmp) {
  			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  			if (info->control.vif == &sdata->vif) {
  				__skb_unlink(skb, &local->pending[i]);
  				dev_kfree_skb_irq(skb);
  			}
  		}
  	}
  	spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);

  }
  
  static int ieee80211_stop(struct net_device *dev)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  
  	ieee80211_do_stop(sdata, true);

  	return 0;
  }
  
  static void ieee80211_set_multicast_list(struct net_device *dev)
  {

  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	struct ieee80211_local *local = sdata->local;

  	int allmulti, promisc, sdata_allmulti, sdata_promisc;
  
  	allmulti = !!(dev->flags & IFF_ALLMULTI);
  	promisc = !!(dev->flags & IFF_PROMISC);
  	sdata_allmulti = !!(sdata->flags & IEEE80211_SDATA_ALLMULTI);
  	sdata_promisc = !!(sdata->flags & IEEE80211_SDATA_PROMISC);
  
  	if (allmulti != sdata_allmulti) {
  		if (dev->flags & IFF_ALLMULTI)
  			atomic_inc(&local->iff_allmultis);
  		else
  			atomic_dec(&local->iff_allmultis);
  		sdata->flags ^= IEEE80211_SDATA_ALLMULTI;
  	}
  
  	if (promisc != sdata_promisc) {
  		if (dev->flags & IFF_PROMISC)
  			atomic_inc(&local->iff_promiscs);
  		else
  			atomic_dec(&local->iff_promiscs);
  		sdata->flags ^= IEEE80211_SDATA_PROMISC;
  	}

  	spin_lock_bh(&local->filter_lock);

  	__hw_addr_sync(&local->mc_list, &dev->mc, dev->addr_len);

  	spin_unlock_bh(&local->filter_lock);

  	ieee80211_queue_work(&local->hw, &local->reconfig_filter);

  }

  /*
   * Called when the netdev is removed or, by the code below, before
   * the interface type changes.
   */
  static void ieee80211_teardown_sdata(struct net_device *dev)

  {

  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;

  	int flushed;

  	int i;

  	/* free extra data */
  	ieee80211_free_keys(sdata);

  	ieee80211_debugfs_remove_netdev(sdata);

  	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)

  		__skb_queue_purge(&sdata->fragments[i].skb_list);
  	sdata->fragment_next = 0;

  	if (ieee80211_vif_is_mesh(&sdata->vif))
  		mesh_rmc_free(sdata);

  
  	flushed = sta_info_flush(local, sdata);
  	WARN_ON(flushed);

  }

  static u16 ieee80211_netdev_select_queue(struct net_device *dev,
  					 struct sk_buff *skb)
  {
  	return ieee80211_select_queue(IEEE80211_DEV_TO_SUB_IF(dev), skb);
  }

  static const struct net_device_ops ieee80211_dataif_ops = {
  	.ndo_open		= ieee80211_open,
  	.ndo_stop		= ieee80211_stop,
  	.ndo_uninit		= ieee80211_teardown_sdata,
  	.ndo_start_xmit		= ieee80211_subif_start_xmit,

  	.ndo_set_rx_mode	= ieee80211_set_multicast_list,

  	.ndo_change_mtu 	= ieee80211_change_mtu,

  	.ndo_set_mac_address 	= ieee80211_change_mac,

  	.ndo_select_queue	= ieee80211_netdev_select_queue,

  };

  static u16 ieee80211_monitor_select_queue(struct net_device *dev,
  					  struct sk_buff *skb)
  {
  	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  	struct ieee80211_local *local = sdata->local;
  	struct ieee80211_hdr *hdr;
  	struct ieee80211_radiotap_header *rtap = (void *)skb->data;
  
  	if (local->hw.queues < 4)
  		return 0;
  
  	if (skb->len < 4 ||

  	    skb->len < le16_to_cpu(rtap->it_len) + 2 /* frame control */)

  		return 0; /* doesn't matter, frame will be dropped */

  	hdr = (void *)((u8 *)skb->data + le16_to_cpu(rtap->it_len));

  	return ieee80211_select_queue_80211(local, skb, hdr);

  }

  static const struct net_device_ops ieee80211_monitorif_ops = {
  	.ndo_open		= ieee80211_open,
  	.ndo_stop		= ieee80211_stop,
  	.ndo_uninit		= ieee80211_teardown_sdata,
  	.ndo_start_xmit		= ieee80211_monitor_start_xmit,

  	.ndo_set_rx_mode	= ieee80211_set_multicast_list,

  	.ndo_change_mtu 	= ieee80211_change_mtu,
  	.ndo_set_mac_address 	= eth_mac_addr,

  	.ndo_select_queue	= ieee80211_monitor_select_queue,

  };
  
  static void ieee80211_if_setup(struct net_device *dev)
  {
  	ether_setup(dev);

  	dev->priv_flags &= ~IFF_TX_SKB_SHARING;

  	dev->netdev_ops = &ieee80211_dataif_ops;

  	dev->destructor = free_netdev;
  }

  static void ieee80211_iface_work(struct work_struct *work)
  {
  	struct ieee80211_sub_if_data *sdata =
  		container_of(work, struct ieee80211_sub_if_data, work);
  	struct ieee80211_local *local = sdata->local;
  	struct sk_buff *skb;

  	struct sta_info *sta;

  	struct ieee80211_ra_tid *ra_tid;

  
  	if (!ieee80211_sdata_running(sdata))
  		return;
  
  	if (local->scanning)
  		return;
  
  	/*
  	 * ieee80211_queue_work() should have picked up most cases,
  	 * here we'll pick the rest.
  	 */
  	if (WARN(local->suspended,
  		 "interface work scheduled while going to suspend
  "))
  		return;
  
  	/* first process frames */
  	while ((skb = skb_dequeue(&sdata->skb_queue))) {

  		struct ieee80211_mgmt *mgmt = (void *)skb->data;

  		if (skb->pkt_type == IEEE80211_SDATA_QUEUE_AGG_START) {
  			ra_tid = (void *)&skb->cb;
  			ieee80211_start_tx_ba_cb(&sdata->vif, ra_tid->ra,
  						 ra_tid->tid);
  		} else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_AGG_STOP) {
  			ra_tid = (void *)&skb->cb;
  			ieee80211_stop_tx_ba_cb(&sdata->vif, ra_tid->ra,
  						ra_tid->tid);
  		} else if (ieee80211_is_action(mgmt->frame_control) &&
  			   mgmt->u.action.category == WLAN_CATEGORY_BACK) {

  			int len = skb->len;

  			mutex_lock(&local->sta_mtx);

  			sta = sta_info_get_bss(sdata, mgmt->sa);

  			if (sta) {
  				switch (mgmt->u.action.u.addba_req.action_code) {
  				case WLAN_ACTION_ADDBA_REQ:
  					ieee80211_process_addba_request(
  							local, sta, mgmt, len);
  					break;
  				case WLAN_ACTION_ADDBA_RESP:
  					ieee80211_process_addba_resp(local, sta,
  								     mgmt, len);
  					break;
  				case WLAN_ACTION_DELBA:
  					ieee80211_process_delba(sdata, sta,
  								mgmt, len);
  					break;
  				default:
  					WARN_ON(1);
  					break;
  				}
  			}

  			mutex_unlock(&local->sta_mtx);

  		} else if (ieee80211_is_data_qos(mgmt->frame_control)) {
  			struct ieee80211_hdr *hdr = (void *)mgmt;
  			/*
  			 * So the frame isn't mgmt, but frame_control
  			 * is at the right place anyway, of course, so
  			 * the if statement is correct.
  			 *
  			 * Warn if we have other data frame types here,
  			 * they must not get here.
  			 */
  			WARN_ON(hdr->frame_control &
  					cpu_to_le16(IEEE80211_STYPE_NULLFUNC));
  			WARN_ON(!(hdr->seq_ctrl &
  					cpu_to_le16(IEEE80211_SCTL_FRAG)));
  			/*
  			 * This was a fragment of a frame, received while
  			 * a block-ack session was active. That cannot be
  			 * right, so terminate the session.
  			 */

  			mutex_lock(&local->sta_mtx);

  			sta = sta_info_get_bss(sdata, mgmt->sa);

  			if (sta) {
  				u16 tid = *ieee80211_get_qos_ctl(hdr) &
  						IEEE80211_QOS_CTL_TID_MASK;
  
  				__ieee80211_stop_rx_ba_session(
  					sta, tid, WLAN_BACK_RECIPIENT,

  					WLAN_REASON_QSTA_REQUIRE_SETUP,
  					true);

  			}

  			mutex_unlock(&local->sta_mtx);

  		} else switch (sdata->vif.type) {

  		case NL80211_IFTYPE_STATION:
  			ieee80211_sta_rx_queued_mgmt(sdata, skb);
  			break;
  		case NL80211_IFTYPE_ADHOC:
  			ieee80211_ibss_rx_queued_mgmt(sdata, skb);
  			break;
  		case NL80211_IFTYPE_MESH_POINT:
  			if (!ieee80211_vif_is_mesh(&sdata->vif))
  				break;
  			ieee80211_mesh_rx_queued_mgmt(sdata, skb);
  			break;
  		default:
  			WARN(1, "frame for unexpected interface type");

  			break;
  		}

  
  		kfree_skb(skb);

  	}
  
  	/* then other type-dependent work */
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_STATION:
  		ieee80211_sta_work(sdata);
  		break;
  	case NL80211_IFTYPE_ADHOC:
  		ieee80211_ibss_work(sdata);
  		break;
  	case NL80211_IFTYPE_MESH_POINT:
  		if (!ieee80211_vif_is_mesh(&sdata->vif))
  			break;
  		ieee80211_mesh_work(sdata);
  		break;
  	default:
  		break;
  	}
  }

  /*
   * Helper function to initialise an interface to a specific type.
   */
  static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata,

  				  enum nl80211_iftype type)

  {

  	/* clear type-dependent union */
  	memset(&sdata->u, 0, sizeof(sdata->u));
  
  	/* and set some type-dependent values */
  	sdata->vif.type = type;

  	sdata->vif.p2p = false;

  	sdata->dev->netdev_ops = &ieee80211_dataif_ops;

  	sdata->wdev.iftype = type;

  	sdata->control_port_protocol = cpu_to_be16(ETH_P_PAE);
  	sdata->control_port_no_encrypt = false;

  	sdata->noack_map = 0;

  	/* only monitor differs */
  	sdata->dev->type = ARPHRD_ETHER;

  	skb_queue_head_init(&sdata->skb_queue);

  	INIT_WORK(&sdata->work, ieee80211_iface_work);

  	switch (type) {

  	case NL80211_IFTYPE_P2P_GO:
  		type = NL80211_IFTYPE_AP;
  		sdata->vif.type = type;
  		sdata->vif.p2p = true;
  		/* fall through */

  	case NL80211_IFTYPE_AP:

  		skb_queue_head_init(&sdata->u.ap.ps_bc_buf);
  		INIT_LIST_HEAD(&sdata->u.ap.vlans);
  		break;

  	case NL80211_IFTYPE_P2P_CLIENT:
  		type = NL80211_IFTYPE_STATION;
  		sdata->vif.type = type;
  		sdata->vif.p2p = true;
  		/* fall through */

  	case NL80211_IFTYPE_STATION:

  		ieee80211_sta_setup_sdata(sdata);

  		break;

  	case NL80211_IFTYPE_ADHOC:
  		ieee80211_ibss_setup_sdata(sdata);
  		break;

  	case NL80211_IFTYPE_MESH_POINT:

  		if (ieee80211_vif_is_mesh(&sdata->vif))
  			ieee80211_mesh_init_sdata(sdata);
  		break;

  	case NL80211_IFTYPE_MONITOR:

  		sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP;

  		sdata->dev->netdev_ops = &ieee80211_monitorif_ops;

  		sdata->u.mntr_flags = MONITOR_FLAG_CONTROL |
  				      MONITOR_FLAG_OTHER_BSS;
  		break;

  	case NL80211_IFTYPE_WDS:
  	case NL80211_IFTYPE_AP_VLAN:

  		break;

  	case NL80211_IFTYPE_UNSPECIFIED:

  	case NUM_NL80211_IFTYPES:

  		BUG();
  		break;
  	}
  
  	ieee80211_debugfs_add_netdev(sdata);
  }

  static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata,
  					   enum nl80211_iftype type)
  {
  	struct ieee80211_local *local = sdata->local;
  	int ret, err;

  	enum nl80211_iftype internal_type = type;
  	bool p2p = false;

  
  	ASSERT_RTNL();
  
  	if (!local->ops->change_interface)
  		return -EBUSY;
  
  	switch (sdata->vif.type) {
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_ADHOC:
  		/*
  		 * Could maybe also all others here?
  		 * Just not sure how that interacts
  		 * with the RX/config path e.g. for
  		 * mesh.
  		 */
  		break;
  	default:
  		return -EBUSY;
  	}
  
  	switch (type) {
  	case NL80211_IFTYPE_AP:
  	case NL80211_IFTYPE_STATION:
  	case NL80211_IFTYPE_ADHOC:
  		/*
  		 * Could probably support everything
  		 * but WDS here (WDS do_open can fail
  		 * under memory pressure, which this
  		 * code isn't prepared to handle).
  		 */
  		break;

  	case NL80211_IFTYPE_P2P_CLIENT:
  		p2p = true;
  		internal_type = NL80211_IFTYPE_STATION;
  		break;
  	case NL80211_IFTYPE_P2P_GO:
  		p2p = true;
  		internal_type = NL80211_IFTYPE_AP;
  		break;

  	default:
  		return -EBUSY;
  	}

  	ret = ieee80211_check_concurrent_iface(sdata, internal_type);

  	if (ret)
  		return ret;
  
  	ieee80211_do_stop(sdata, false);
  
  	ieee80211_teardown_sdata(sdata->dev);

  	ret = drv_change_interface(local, sdata, internal_type, p2p);

  	if (ret)
  		type = sdata->vif.type;
  
  	ieee80211_setup_sdata(sdata, type);
  
  	err = ieee80211_do_open(sdata->dev, false);
  	WARN(err, "type change: do_open returned %d", err);
  
  	return ret;
  }

  int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,

  			     enum nl80211_iftype type)

  {

  	int ret;

  	ASSERT_RTNL();

  	if (type == ieee80211_vif_type_p2p(&sdata->vif))

  		return 0;

  	/* Setting ad-hoc mode on non-IBSS channel is not supported. */

  	if (sdata->local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS &&
  	    type == NL80211_IFTYPE_ADHOC)

  		return -EOPNOTSUPP;

  	if (ieee80211_sdata_running(sdata)) {
  		ret = ieee80211_runtime_change_iftype(sdata, type);
  		if (ret)
  			return ret;
  	} else {
  		/* Purge and reset type-dependent state. */
  		ieee80211_teardown_sdata(sdata->dev);
  		ieee80211_setup_sdata(sdata, type);
  	}

  
  	/* reset some values that shouldn't be kept across type changes */

  	sdata->vif.bss_conf.basic_rates =

  		ieee80211_mandatory_rates(sdata->local,
  			sdata->local->hw.conf.channel->band);

  	sdata->drop_unencrypted = 0;

  	if (type == NL80211_IFTYPE_STATION)
  		sdata->u.mgd.use_4addr = false;

  
  	return 0;

  }

  static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
  				       struct net_device *dev,
  				       enum nl80211_iftype type)
  {
  	struct ieee80211_sub_if_data *sdata;
  	u64 mask, start, addr, val, inc;
  	u8 *m;
  	u8 tmp_addr[ETH_ALEN];
  	int i;
  
  	/* default ... something at least */
  	memcpy(dev->perm_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
  
  	if (is_zero_ether_addr(local->hw.wiphy->addr_mask) &&
  	    local->hw.wiphy->n_addresses <= 1)
  		return;
  
  
  	mutex_lock(&local->iflist_mtx);
  
  	switch (type) {
  	case NL80211_IFTYPE_MONITOR:
  		/* doesn't matter */
  		break;
  	case NL80211_IFTYPE_WDS:
  	case NL80211_IFTYPE_AP_VLAN:
  		/* match up with an AP interface */
  		list_for_each_entry(sdata, &local->interfaces, list) {
  			if (sdata->vif.type != NL80211_IFTYPE_AP)
  				continue;
  			memcpy(dev->perm_addr, sdata->vif.addr, ETH_ALEN);
  			break;
  		}
  		/* keep default if no AP interface present */
  		break;
  	default:
  		/* assign a new address if possible -- try n_addresses first */
  		for (i = 0; i < local->hw.wiphy->n_addresses; i++) {
  			bool used = false;
  
  			list_for_each_entry(sdata, &local->interfaces, list) {
  				if (memcmp(local->hw.wiphy->addresses[i].addr,
  					   sdata->vif.addr, ETH_ALEN) == 0) {
  					used = true;
  					break;
  				}
  			}
  
  			if (!used) {
  				memcpy(dev->perm_addr,
  				       local->hw.wiphy->addresses[i].addr,
  				       ETH_ALEN);
  				break;
  			}
  		}
  
  		/* try mask if available */
  		if (is_zero_ether_addr(local->hw.wiphy->addr_mask))
  			break;
  
  		m = local->hw.wiphy->addr_mask;
  		mask =	((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  			((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  			((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  		if (__ffs64(mask) + hweight64(mask) != fls64(mask)) {
  			/* not a contiguous mask ... not handled now! */
  			printk(KERN_DEBUG "not contiguous
  ");
  			break;
  		}
  
  		m = local->hw.wiphy->perm_addr;
  		start = ((u64)m[0] << 5*8) | ((u64)m[1] << 4*8) |
  			((u64)m[2] << 3*8) | ((u64)m[3] << 2*8) |
  			((u64)m[4] << 1*8) | ((u64)m[5] << 0*8);
  
  		inc = 1ULL<<__ffs64(mask);
  		val = (start & mask);
  		addr = (start & ~mask) | (val & mask);
  		do {
  			bool used = false;
  
  			tmp_addr[5] = addr >> 0*8;
  			tmp_addr[4] = addr >> 1*8;
  			tmp_addr[3] = addr >> 2*8;
  			tmp_addr[2] = addr >> 3*8;
  			tmp_addr[1] = addr >> 4*8;
  			tmp_addr[0] = addr >> 5*8;
  
  			val += inc;
  
  			list_for_each_entry(sdata, &local->interfaces, list) {
  				if (memcmp(tmp_addr, sdata->vif.addr,
  							ETH_ALEN) == 0) {
  					used = true;
  					break;
  				}
  			}
  
  			if (!used) {
  				memcpy(dev->perm_addr, tmp_addr, ETH_ALEN);
  				break;
  			}
  			addr = (start & ~mask) | (val & mask);
  		} while (addr != start);
  
  		break;
  	}
  
  	mutex_unlock(&local->iflist_mtx);
  }

  int ieee80211_if_add(struct ieee80211_local *local, const char *name,

  		     struct net_device **new_dev, enum nl80211_iftype type,

  		     struct vif_params *params)

  {
  	struct net_device *ndev;

  	struct ieee80211_sub_if_data *sdata = NULL;

  	int ret, i;

  
  	ASSERT_RTNL();

  	ndev = alloc_netdev_mqs(sizeof(*sdata) + local->hw.vif_data_size,
  				name, ieee80211_if_setup, local->hw.queues, 1);

  	if (!ndev)
  		return -ENOMEM;

  	dev_net_set(ndev, wiphy_net(local->hw.wiphy));

  	ndev->needed_headroom = local->tx_headroom +
  				4*6 /* four MAC addresses */
  				+ 2 + 2 + 2 + 2 /* ctl, dur, seq, qos */
  				+ 6 /* mesh */
  				+ 8 /* rfc1042/bridge tunnel */
  				- ETH_HLEN /* ethernet hard_header_len */
  				+ IEEE80211_ENCRYPT_HEADROOM;
  	ndev->needed_tailroom = IEEE80211_ENCRYPT_TAILROOM;

  	ret = dev_alloc_name(ndev, ndev->name);
  	if (ret < 0)
  		goto fail;

  	ieee80211_assign_perm_addr(local, ndev, type);
  	memcpy(ndev->dev_addr, ndev->perm_addr, ETH_ALEN);

  	SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));

  	/* don't use IEEE80211_DEV_TO_SUB_IF because it checks too much */
  	sdata = netdev_priv(ndev);

  	ndev->ieee80211_ptr = &sdata->wdev;

  	memcpy(sdata->vif.addr, ndev->dev_addr, ETH_ALEN);
  	memcpy(sdata->name, ndev->name, IFNAMSIZ);

  
  	/* initialise type-independent data */

  	sdata->wdev.wiphy = local->hw.wiphy;

  	sdata->local = local;

  	sdata->dev = ndev;

  #ifdef CONFIG_INET
  	sdata->arp_filter_state = true;
  #endif

  
  	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
  		skb_queue_head_init(&sdata->fragments[i].skb_list);
  
  	INIT_LIST_HEAD(&sdata->key_list);

  	for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
  		struct ieee80211_supported_band *sband;
  		sband = local->hw.wiphy->bands[i];
  		sdata->rc_rateidx_mask[i] =
  			sband ? (1 << sband->n_bitrates) - 1 : 0;
  	}

  
  	/* setup type-dependent data */
  	ieee80211_setup_sdata(sdata, type);

  	if (params) {
  		ndev->ieee80211_ptr->use_4addr = params->use_4addr;
  		if (type == NL80211_IFTYPE_STATION)
  			sdata->u.mgd.use_4addr = params->use_4addr;
  	}

  	ret = register_netdevice(ndev);
  	if (ret)
  		goto fail;

  	mutex_lock(&local->iflist_mtx);

  	list_add_tail_rcu(&sdata->list, &local->interfaces);

  	mutex_unlock(&local->iflist_mtx);

  	if (new_dev)
  		*new_dev = ndev;

  	return 0;

   fail:

  	free_netdev(ndev);
  	return ret;
  }

  void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)

  {

  	ASSERT_RTNL();

  	mutex_lock(&sdata->local->iflist_mtx);

  	list_del_rcu(&sdata->list);

  	mutex_unlock(&sdata->local->iflist_mtx);

  	if (ieee80211_vif_is_mesh(&sdata->vif))
  		mesh_path_flush_by_iface(sdata);

  	synchronize_rcu();

  	unregister_netdevice(sdata->dev);

  }

  /*
   * Remove all interfaces, may only be called at hardware unregistration
   * time because it doesn't do RCU-safe list removals.
   */
  void ieee80211_remove_interfaces(struct ieee80211_local *local)

  {

  	struct ieee80211_sub_if_data *sdata, *tmp;

  	LIST_HEAD(unreg_list);

  
  	ASSERT_RTNL();

  	mutex_lock(&local->iflist_mtx);

  	list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
  		list_del(&sdata->list);

  		if (ieee80211_vif_is_mesh(&sdata->vif))
  			mesh_path_flush_by_iface(sdata);

  		unregister_netdevice_queue(sdata->dev, &unreg_list);

  	}

  	mutex_unlock(&local->iflist_mtx);
  	unregister_netdevice_many(&unreg_list);

  	list_del(&unreg_list);

  }

  
  static u32 ieee80211_idle_off(struct ieee80211_local *local,
  			      const char *reason)
  {
  	if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
  		return 0;
  
  #ifdef CONFIG_MAC80211_VERBOSE_DEBUG

  	wiphy_debug(local->hw.wiphy, "device no longer idle - %s
  ", reason);

  #endif
  
  	local->hw.conf.flags &= ~IEEE80211_CONF_IDLE;
  	return IEEE80211_CONF_CHANGE_IDLE;
  }
  
  static u32 ieee80211_idle_on(struct ieee80211_local *local)
  {
  	if (local->hw.conf.flags & IEEE80211_CONF_IDLE)
  		return 0;
  
  #ifdef CONFIG_MAC80211_VERBOSE_DEBUG

  	wiphy_debug(local->hw.wiphy, "device now idle
  ");

  #endif

  	drv_flush(local, false);

  	local->hw.conf.flags |= IEEE80211_CONF_IDLE;
  	return IEEE80211_CONF_CHANGE_IDLE;
  }
  
  u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
  {
  	struct ieee80211_sub_if_data *sdata;
  	int count = 0;

  	bool working = false, scanning = false, hw_roc = false;

  	struct ieee80211_work *wk;

  	unsigned int led_trig_start = 0, led_trig_stop = 0;

  #ifdef CONFIG_PROVE_LOCKING
  	WARN_ON(debug_locks && !lockdep_rtnl_is_held() &&
  		!lockdep_is_held(&local->iflist_mtx));
  #endif
  	lockdep_assert_held(&local->mtx);

  
  	list_for_each_entry(sdata, &local->interfaces, list) {

  		if (!ieee80211_sdata_running(sdata)) {
  			sdata->vif.bss_conf.idle = true;

  			continue;

  		}
  
  		sdata->old_idle = sdata->vif.bss_conf.idle;

  		/* do not count disabled managed interfaces */
  		if (sdata->vif.type == NL80211_IFTYPE_STATION &&

  		    !sdata->u.mgd.associated) {
  			sdata->vif.bss_conf.idle = true;

  			continue;

  		}

  		/* do not count unused IBSS interfaces */
  		if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&

  		    !sdata->u.ibss.ssid_len) {
  			sdata->vif.bss_conf.idle = true;

  			continue;

  		}

  		/* count everything else */
  		count++;
  	}

  	list_for_each_entry(wk, &local->work_list, list) {
  		working = true;
  		wk->sdata->vif.bss_conf.idle = false;
  	}
  
  	if (local->scan_sdata) {
  		scanning = true;
  		local->scan_sdata->vif.bss_conf.idle = false;
  	}

  	if (local->hw_roc_channel)
  		hw_roc = true;

  	list_for_each_entry(sdata, &local->interfaces, list) {
  		if (sdata->old_idle == sdata->vif.bss_conf.idle)
  			continue;
  		if (!ieee80211_sdata_running(sdata))
  			continue;
  		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
  	}

  	if (working || scanning || hw_roc)

  		led_trig_start |= IEEE80211_TPT_LEDTRIG_FL_WORK;
  	else
  		led_trig_stop |= IEEE80211_TPT_LEDTRIG_FL_WORK;
  
  	if (count)
  		led_trig_start |= IEEE80211_TPT_LEDTRIG_FL_CONNECTED;
  	else
  		led_trig_stop |= IEEE80211_TPT_LEDTRIG_FL_CONNECTED;
  
  	ieee80211_mod_tpt_led_trig(local, led_trig_start, led_trig_stop);

  	if (hw_roc)
  		return ieee80211_idle_off(local, "hw remain-on-channel");

  	if (working)
  		return ieee80211_idle_off(local, "working");
  	if (scanning)
  		return ieee80211_idle_off(local, "scanning");

  	if (!count)
  		return ieee80211_idle_on(local);
  	else
  		return ieee80211_idle_off(local, "in use");
  
  	return 0;
  }
  
  void ieee80211_recalc_idle(struct ieee80211_local *local)
  {
  	u32 chg;
  
  	mutex_lock(&local->iflist_mtx);
  	chg = __ieee80211_recalc_idle(local);
  	mutex_unlock(&local->iflist_mtx);

  	if (chg)
  		ieee80211_hw_config(local, chg);

  }

  
  static int netdev_notify(struct notifier_block *nb,
  			 unsigned long state,
  			 void *ndev)
  {
  	struct net_device *dev = ndev;
  	struct ieee80211_sub_if_data *sdata;
  
  	if (state != NETDEV_CHANGENAME)
  		return 0;
  
  	if (!dev->ieee80211_ptr || !dev->ieee80211_ptr->wiphy)
  		return 0;
  
  	if (dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
  		return 0;
  
  	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

  	memcpy(sdata->name, dev->name, IFNAMSIZ);

  
  	ieee80211_debugfs_rename_netdev(sdata);
  	return 0;
  }
  
  static struct notifier_block mac80211_netdev_notifier = {
  	.notifier_call = netdev_notify,
  };
  
  int ieee80211_iface_init(void)
  {
  	return register_netdevice_notifier(&mac80211_netdev_notifier);
  }
  
  void ieee80211_iface_exit(void)
  {
  	unregister_netdevice_notifier(&mac80211_netdev_notifier);
  }